During start-up of a conventional eight cylinder diesel engine, a charge of fuel is injected into each combustion chamber thereof and ignited due to the heat of compression. Fuel is alternately injected into each combustion chamber by a pump of a conventional sleeve metering fuel system having a plunger which reciprocates in response to rotation of an engine-driven cam shaft.
Until the engine warms up, operation of all eight cylinders gives rise to a "white smoke" condition of engine operation. Such condition occurs during cold start-up since engine exhaust contains an overabundant amount of irritants, such as hydrocarbons, aldehydes and oxides of nitrogen. This condition is primarily occasioned by the cold air which provides a disproportionate air-fuel mixture which normally approximates 15:1 to 22:1 upon warm-up of the engine.